package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已完成登录
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //获取用户访问路径
        String requestURI = request.getRequestURI();
        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };
        //判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //不需要处理，直接放行
        if (check){
            log.info("本次请求{}不需要被处理",request.getRequestURI());
            filterChain.doFilter(request,response);
            return;
        }
        //用户已登录，直接放行
        if (request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("employee"));
            filterChain.doFilter(request,response);
            return;
        }
        //用户未登录，向客户端页面响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
     }

    /**
     *匹配本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
     public static boolean check(String[] urls,String requestURI){
         for (String url : urls) {
             boolean check = PATH_MATCHER.match(url, requestURI);
             if (check){
                 return true;
             }
         }
         return false;
     }
}
